Such a method is inter alia particularly suitable for the manufacture of so-called buried hetero-junction semiconductor diode lasers, especially if the latter are entirely manufactured by means of OMVPE (=Organo-Metallic Vapour Phase Epitaxy) as a growing technique. However, also other semiconductor diode lasers, such as those of the ridge type, other opto-electronic devices, such as LED's, and photodiodes and electronic devices, such as transistors, may advantageously be manufactured by such a method. More particularly the method is suitable for manufacturing devices in III-V material systems.
Such a method is known from the abstract in the English language of Japanese Kokai 63-177493 (date of publication Jul. 7, 1988), which is published in Pat. Abstracts of Japan, Vol. 12, Nov. 25, 1988, No. 449 (E-686), pag. 81. It is described therein how a mesa is formed at a surface of a semiconductor body comprising a semiconductor substrate provided with two cladding layers, between which an active layer is disposed and on which a top layer is disposed. Subsequently, in a second growing process, by means of MOVPE a semiconductor layer structure is provided on and beside the mesa, which structure comprises two semiconductor layers, which are interrupted at the area of the sidewalls of the mesa and form on either side of the mesa current-blocking layers in a semiconductor diode laser of the buried hetero-junction type to be realized. Finally, from a semiconductor layer other than the last semiconductor layer, in this case from the first semiconductor layer, the parts of the semiconductor layers located above the mesa, in this case of the first and second semiconductor layers, are removed by means of a lift-off step in that the top layer of the mesa is removed by etching. The top layer is removed by means of an etchant selective with respect to the last, in this case the second, semiconductor layer and selective with respect to the subjacent semiconductor layer forming part of the mesa. At the area of the mesa, the upper cladding layer is then exposed.
A disadvantage of the known method is that after the second growing process, in which the current-blocking layers are formed, and after the removal of the parts of said the layers located above the mesa, a third growing process is necessary to finish the semiconductor diode laser. In fact, it is often very difficult and for some materials even substantially impossible to establish a good connection contact directly on the upper cladding layer. As a result, it becomes necessary to provide in a third growing process a semiconductor layer acting as a contact layer. In the known method, use is indeed made of this third growing process. The use of many growing processes is laborious and hence expensive, however, and reduces the yield.